Apparatus for tube bending



Aug. 28, 1951 A. v. BROGREN 2,565,717

APPARATUS FOR TUBE BENDING Filed July 9, 1948 10 Sheets-Sheet 1 BIKE-4.-

INVENTOR. 1434-2 1 5RO6RA/ A TIDE/14575 Aug. 28, 1951 A. v. BROGREN 2,565,717

APPARATUS FOR TUBE BENDING Filed July 9, 1948 1o Sheets-Sheet 2 INVENTOR.

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APPARATUS FOR TUBE BENDING Filed July 9, 1948 10 Sheets-Sheet 4 L9 no :EIE: ll]

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APPARATUS FOR TUBE BENDING Filed July 9, 1948 10 Sheets-Sheet 10 IE 113-. 3 E

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Patented Aug. 28, 1 951- mesne assignments, to. Parsons Co porationI Detroit, Mi'chi, a corpoiatiiiii' of lvfiiihi gan" I Application'July 9,1948, Serial N0. 37,757' -I 1 This invention relates 'to' an improved apparatus for bending tubes or the like; I

An object is toprovide an improved apparatus whereby tubes, rods or other similar elongate structural members maybe bent, into desired shapes quickly, easily, accurately, and withoutmutilation. V

Another object is to provide anapparatuswhich requires a minimum amount of space in the shop, the apparatus being disposed largely. 193

in an upright positiom- The apparatus requires the attendanceoi a-minimum number of workers. The apparatus is of. simple, rugged, inexpensive construction.

Animportant feature of theinvention is that 15 the tubes or other pieces which'are shaped by the v apparatus may. be bent tothe desired curvature in an accurate manner without mutilation or breakage. The-machine is ofsuch a character.

thata-long tube may have a plurality of bends 2Q simultaneously imparted thereto. I e v The entire apparatus'herein disclosed includestwo' separate mechanisms One mechanism is. adapted to impart a certain series ofbends to a tube; Another'mechanism'is adapted tc there- 5 after impart another series of bends tothe same tube. Both mechanisms may function simultaneously to carryout operations upon two separate tubes eachcarrying out its'own seriesjof.

operations. I s V I M Heretofore, tubes'havebeen bentbywrapping" the tube about a forming-roll or segment which waseither stationary or was rotatable about a fixed pivot. In the one case, the tube was wrapped aboutastationary mn'py a pressure" 35: H v e I V H H w I H w course, applicable tp the'beiiding'iof rods or other member which was swung about the arcuate tube forming face of the roll; As it swun'g it bent the tube about the arcuate faceof-the roll; The tube was-heldstationary as-to lengthwise mtvemem and the pressuremember was wiped over the tube- 49 about the roll. In the other case the-tube was clamped to the arcuate face of'a-forming roll which was supported to rotate about a fixed pivot; The tube washeld by a grooved block to the roll. The roll was thenrotated drawing the 5 tube lengthwise and wrapping the tubela-boiit the roll. In both cases there was danger of rnutilation of the tube bydrawing the tube lengthwise over a holding-member or advancinga pressure memberlengthwise over thet'ub;

In this invention thetube is wrapped: about aforming roll or arcuate part which rotates about a-center which centeris advanced parallel to the tube. The forming-roll revolves along-a path parallel to thetube as the roll rotates;

' Fir. 1 following the" completio I ll/lore particularly an important feature ofitlie apparatus is that it includes means forsupporting a tube in part along apathway over a forming roll or disc supported ior rotatable travel. Means is provided for clamping one end;

' of the 7 supported tube to :the roll to wrap about he i h r th reo t e 2.9 l ese li i the pathway t e by-A t ies a .P meeeet e d o the-:l ubeh. oth 2 .41 .9. th ub zme b bent simultaneously, two forming rollsbeing pro: vided to act on the two ends of the'tube at one nq he me me By securing the tube-to anf arcuat for; face I which rotates about acen'ter' and" revel s at the same m le-Lapses pa allel'to thes'up ported tube, the'tu'be is be twitliout"mutilation;

scarring or other deface'njiei it. I e I Specifically the Menuhin illustrated in connection with" the fab? "atibii er a ehic e seat frame wherein the frame is. mines of tubul 'r" members shaped to pr'ovide'a seat portion a d a back portion. It is apparent that theiiivention might be appliedito the 'ber'idiiig'oftubs er ot e Siifi flar st r llbtllial parts ifitO Othe r and differ erit shapes; I a a The several figures of the drawings illustrate:

the Steps i t e Pro f ,carryineoi t' my invention asia'pjplid" to 'tlie'bendirig drfa' tube or"pipe into the forml off a tubuiarseat name.

i and illustratetheimprovedmechanism employeif mule aarrymgmt ofsucli'proces's, owever? the. mention is applicable to the riding gr 'tup'es or the. like: into other s r ural" shapes; a'fnd designs. Whilethe" inventionis illustrated as, employed in the bending of a"t'ube",. it. is j of elon atestructurai'members: I I; Other objects, advantages and meritorious" features will more iti1 y.app"""rf m th'lfollo'wing description, claiifis a'iiddraw s; wherein 531g; 1 isari elevat ori dlii'gthidr tubing-suitable for being subjeetedito thprocss of my invention as herein "disclosed; I

2' is an elevation of;theiltube showii.in. Fig. 1 renewing; the" carrying out ofnth e firstbending step'inxt e tcess off this invention-.

Fig 3 is an elevation of the tubeshown in Fig. 1 fOllOWil'lgi the: completion of the" second bendingstep inthfef rdc essfof this invention.-

Fig. 4 is an; deta ned of the tube shownl in: of V the. bird bendingstep in the process of this "entioiil.

Fig. 5 illustrates the? form; shbwriin Fig. 4 following the welding. ofith r ee separate Fig. 6 illustrates the tubular structure of Fig.

Fig. 8 is an elevation of a fragment of the struc' ture shown in Fig. 7 and also illustrating the completion of the first bending step in the process of this invention.

Fig. 9 is an elevation of the structure shown in V Fig. 8 and differing therefrom only in that the working mechanism and the tube operated upon thereby is illustrated at the completion of the second bending step and at the completion of the third bending step in the process.

Fig. 10 is an enlarged sectional View taken on the line Ill-l0 of Fig. 7.

Fig. 11 is an enlarged sectional view taken on the line llll of Fi .--7 I 1 a r "Fig. 12-is an enlarged sectional view taken on the-line IZ-IZ of Fig.7.

Fig.-13 is a sectional viewtaken on the line l-3l3 of Fig. 12.- v

-Fig. 14 is a perspective of that portion of the structure shown in Fig. 8 which embodies the stationary tube clamping mechanism.

Fig. 15 is a sectional view taken on the line |5|5 of Fig.- 14. l

Figu'16 is a perspective of a fragment of the mechanism shown in Fig. 14 illustrating the retainer latch for the clamp member.

Fig. 17 is a perspective of a fragment of one of the lower rotatable tube forming segments and associated clamping fixture.

Fig. 18 is a perspectiveof a fragment of the tube supporting mechanism associated with the upper rotatable tube forming gear and segment.

Fig. 19 is a sectionalview taken on the line l9--l9 of Fig. 8.

Fig. 20 isa sectional view taken on the line 20-20 of Fig. 8 showing the rotatable tube forming segment and gear'showing the clamping fixture closed locking a tube to the forming segment.

Fig. 21 is a sectional view taken on substantially the same line as the view of Fig. 20 showing the clamping fixture partly open.

Fig; 22 is a sectional view taken on substantially the same line as the views of Figs. 20 and 21 showing the clamping fixture open.

'Fig. 23 is a sectional view'taken on the line 23-23 of Fig. 19. I

Fig. 24 is a fragmentary perspective of a positioning stop for one end of the tube shown in Fi 7.

Fig. 25 is a fragmentary sectional view taken on the line 25-25 of Fig. 18.

Fig. 26' is a diagrammatic illustration of hydraulic mechanism adapted to operate the mechanical structure shown in Figs. 7 through 25.

Fig. 27 is an end view of the mechanism provided to bend thetube from the shape shown in Figs. 4 and 5 to that shown in Fig. 6.

Fig.28 is a perspective of a fragment of the tube bending support shown in Fig. 27.

Fig. 29 is an end view of the mechanism shown in Fig. 27 illustrating the tube holding clamp closed and holding the tube against the rotatable forming segment.

Fig. 30 is an elevation of a fragment of the structure shown in Fig. 29.

Fig. 31 is an end elevation of a fragment of the mechanism shown in Fig. 29 illustrating the posi- 4 tion of the parts following the bending of the tube into the form shown in Fig. 6.

Fig. 32 is a plan of the machine shown in Figs. 27 and 29 but illustrating the same following the bending operation illustrated in Fig. 31.

Fig. 33 is a perspective of a broken away fragment of the machine shown in Figs. 27, 29 and 32 showing the partsfollowing the bending operation illustrated in Fig. 32.

Fig. 34 is a diagrammatic illustration of a hydraulic system provided to actuate the mechanism shown in Figs. 27 through 33.

To recapitulate the figures, Fig. 1 illustrates a sec-tion of tubing adapted to be employed in the forming of a tube frame for a seat such as shown in completed form in Fig. 6. Figs. 2 through 5 illustrate this piece of tubing at various stages in the formation of the tubular frame of Fig. 6. Fig. 7"through 25 illustrates the mechanism wherein the tube shown in Fig. 1 is bent into the shape shown in Fig. 4 and Fig. 26 illustrates diagrammatically a hydraulic system which is coupled with and actuates the mechanism shown in Figs. 7 through 25. Figs. 27 through 33 illustrate the mechanism wherein the tubular frame shown in Fig. 4 and Fig. 5 is bent into the form shown in.

Fig. 6, and Fig. 34 diagrammatically illustrates a hydraulic system which is coupled with the mechanism shown in Figs. 27 through 33 to operate the same. r r

In the forming of a tubular seat frame a piece of tubing or pipe 40, Fig. 1, of the required length and diameter is first subjected to a-bending operation which bends up the opposite end portions as at 42, Fig. 2. The extreme ends of these bent up end portions 42' of the tube are'then rolled as at 44 into the shape shown in Fig. 3.

The tube shaped as shown in Fig 3 then is bent as at 46 into a U-shape as shown in Fig. 4. A separate tube section 48 is then welded between the opposite free ends 44 of the U-tube shape. Separate tube sections 50 and 52 are likewise welded into place as shown in Fig. 5. This forms a flat frame structure of the character shown in Fig. 5. Such fiat tubular frame is then bent as at 53 to form the frame for a seat as illustrated in Fig. 6. These operations are carried outin the process herein described and by the employment of the two mechanisms illustrated generally in Figs. 7 and 27.

The structure showngenerally in broken away elevation in Fig. 7 and in the various detail views 8 through 25 is the mechanism whereby a straight length of tube 40 illustrated in Fig. 1 is bent'throughsuccessive steps into a U-shape as shown in Fig. 4. Such-mechanism and its operation by the hydraulic system disclosed in Fig. 26 will be first described.

This structure comprises. a flat foundation board 54 supported in a generally upright position, sloping slightly rearwardly for convenience, by legs-56. Due to the upright position of this board which carries the operating mechanism and the hydraulic system, the structure occupies only a relatively small amount of floor space within a shop. The tube engaging clamps and forming tools are mounted on the front face of the board as shown in Fig. 7. The hydraulic mechanism is mounted in part upon the front clamping and shaping devices-r mantis" A pair-of similar tube clamping-assemblies are mounted onopposite end I portions i of the board" (Fig. 7). Each assemb1y-oomprises a base-plate *6 0 secured: by 'screws' 62 to the-foundation board' 54, Fig: 7. The--screws-62- extend through slots -64 in-thebaseplate-BB whereby the plate may be adiustably Y positioned upon the board 'withinthe-limits of the slots. Astationary tube-clamping and bending block =66 is -fixedto the plate 60 by pins--68-(Fig.-14).- This bloc'k is provided with a bottom working iace grooved to form--a seat -for the tube-as shown'in Figs: 14 and" 16: This working face is of angular' con' tour as illustrated.-

An L-shaped-tube-clampingmember I0 is pivoted at 12 to the plate BB-fo'r swinga-ble-move= ment from the open" position shown-in dotted outline at the bottom of thesheet --in"Fig""7. In the open position atube may be inserted between this swingable clamp= -and the stat-10m aryo'lamp 66; and the swingable clamp-l0=may then be-moved to the closed'solid -line position: The swingable -L-clamp is provided with a handle 16' Fig; 14). In the open -position the clamp is supported upon a stop pin 'I4.- In the closed position the clamp is supported-upon a "rotatable latch.-

The latch IB-is journalled within the plate 60 for-rotation about avertical axis-from the 0p erativepositi'onshown in *solid line in Figs. 14 and 16; at which position the .L -clampds' held elevated thereby,- to the inoperative position shown in" dotted-outline in Fig. 15. When'the latch is in the inoperative position the L- clamp-10 is permitted to-fall -down-to the inoperative position showrr'indotted-"outline show-n in Fig. '7.- A-stop pin 80 determines-the "opera tive-position-of swing of the-latch!!! as shownin Figs. Hand 16. When-a length of'tubing is inserted in place asshow-n in- Fig; "7; the opposite ends of the tube are --posit-i'oned"by positioning blocks =19 as shown in Fig. 7.

A pa-irof hydraulically-actuated tube bending assemblies areprovided and'identified generally by-the-numerals 82(Fig.- 7); These assemblies are mounteduponopposite A ends of the board 54 inproximity tothe pipeclamping assemblies 58 described-abover Thetwo assemblies 82 are similar. They are designed-to act simultane= ously upon opposite ends of thelength of tubing as herein described.

Eachassembly 82, asshown in largerdetail in Figs. 8 and 9, comprises a tube supportingand bending block 84 having an upper working face grooved asindicated in dotted-line at 33in Figs. "8and'9'to seat a "length oftubing as shown particularly in such'figures. This block 84 is mounted upon the free end of a link 88 .'which link is pivoted at its opposite endupon a pivot 00.for raising andlowcring of the block-'84 to bend the tube asshown in Fig. 9.. Thepivot 90 is carried by a plate 92 whichplate-is fixed to the board 54.

A pair of hydraulic piston and cylindersas semblies; eachzcomprising a cylinder 94 pivotally supported :at 96 and a piston 98 reciprocally mounted. withinthe cylinder'and connected at its-outerendwith the block 84, are provided to swing the blocks 84. The piston is adapted to raise the block 84 'from the position shown in Fig-'7 to that shownin Fig. 8 to bendth'e end of the-tube supported upon' the block, as shown at 42. As shown in Fig: 7" these swingably'sup'v ported blocks 84 are 'providedin pairsandthe in Fig. 3. These twoassembliesaresimilar and hydmulic cylinders iare provided 'inr pairs; one for each end-of the boards- A pair of hydraulically operated tube :iorm'ing assemblies indicated (generally -as I 00 i are alsoshown in-Fig. 7. Tl'i'ese assemblies-are mounted upon opposite ends of the. board 54 and adaptedto-roll opposite ends of the tube as shown at 44 are-adapted to be simultaneously hydraulically actuatedto s'imultaneouslybend the oppositeends' of thetube:

Each assembly I 00 comprises a-tu-be-.forming roll or" half-circular segment I02 "fixed inany suitable manner to thezouter face of a gear wheel I04 sear wheel is supported for rotatable travel towrap the endo'f the tube 40about the periphery of thesegment- 'I02" to which' it is clamped as shown inFig'. '9. I he periphery of the segment is grooved as at-I06 (Figs. wand 17) to'receive and seat the tube as shown in Figs. 9' and 17. The gea'r I04 -io'rmsone'of a pair ofge'ar's- The --cooperatihg gear of the-pair is indicated-"as I-08-. The two gears are mounted on opposite ends-oi an axle I IED -(Fig'. 10); The axleextends'i through -a- -s-lotl I2 -(Fig. 8)--inthe board-54 w tr avel-lengthwise therethrough as thegears re-* volve;

The 'gear I04 is supported upon a stationary rack-I I4 which is mounted uponthefront face of the board. This 'rack'is mounted for lengthwise adj'ustmentupon-a supporting bar IIG carried bythe board-.- The supporting-bar -I I6 is secured to the board 54 by screws "H8; The rack is held tethe-iboardbY screws -I20 (Fig: 7)' which screws I20 extend'through s1ots I22 in'the rack-so as to permit slidable lengthWiseadjust-ment ofthe rack upon the bar over the board; Adjustable-stops I 23-(Fig'.= '7) are provided 'in the opposite ends of each supporting bar to' engage the-endsof the rack -I I4 mounted upon the bar.

The-gear I 08, whichis located at the rear of the 'board,'is supportedupona stationary'rack I24 carried bya bar I26 which bar is-secured-by screws or the like I28 to a foundation plate I30 whichplate' is secured-in spaced "relationship from the' board 54 by struts I32. The rack I24 is a'djustable upon its supporting bar I26'in the same manner as rack II4"was heretofore described as being adjustable upon" its supporting rack IIB, being provided with pins I34 carried by the plate I30 'and extending through slots in the rack.

Travel of the gears'IM and I08 over the stati'onary racks I I4 and I24 is provided for by linear movement of slidable racks I36 and I30 respective-ly; These tracks I36 and I38'travel over guide bars I40 and. I42 respectively. The guide bars I40pand'I42'aresecured :byrscrews I44 to the board"54"and "the plate I30, respectively. The slidable'racks I30"and"I38'are held to the guide bars I40 and I42 by splines I46 '(Fig. 10) re-. ceived insplineways I41 formed in the guide bars I40 and I42 (Fig. 11) for guided travelv therethrough.

Theseracksare actuated by the piston I48 of a hydraulic piston and cylinder mechanism. The hydraulic cylinder I50 (Fig. 11) is pivotally sup ported at its closed end upon pivot I52 carried by bracket I54 which bracket is in turn carried by a strut I32. The free end of piston I48 is cou pled-with..the slidable rackssby cross-head: I55 (Fig.-,.11) which cross-head extends through a slot 'I5'8 out in the board 54, Figs..7 andlO. An adjustable screw.stop I60 is threaded into a strut I31"providingv a limit of..slida'ble travel. for the racks [3F and I38" by engaging the cross-head of the segment I02 (Figs. 9 and 12). This clamp:

comprises a supporting base I66 secured to the gear I04 by screws I61 or the like (Fig. 12 The lower end of this base member is grooved as at I68 (Fig. 12) in line with the groove I06 formed in the periphery of the forming segment I02 which segment is also attached to the gearl04.

The upper end of this base member is forked to receive one end of a link I'I0 pivoted therein upon pivot I12. To the opposite end of the link is pivoted a clamp I'I4 by a pivot pin I16 (Figs. 12 and 17). The link is .provided with a handle IIB to swing the link to tighten the clam I74. The lower end, of the clamp is provided with a claw or hook I80 (Fig. 12) adapted toengage a tube seated within the groove I68 of the base member I66 of the clamping mechanism. 7 U

A spring urged ball I82 (Figs. 12 and 13) is provided to releasably hold a clamp H4 in the open position to permit seating of a tube against the grooved periphery I06 of the segment I02 and against the grooved end I68 of the clamping base member I66 as shown in Fig. 12. When the handle I18 is thrown upwardly as shown in Fig. 9 the hook end I80 of the clamp proper I14 engages and holds the tube snugly against the grooved end I68 of the base member I66 of the clamping mechanism-and therefore also holds the tube against the grooved periphery I66 of the segment I02 so that when the segment rotates with the gear I04 the tube is wrapped about the segment to form the bend 44.

The operation of the hydraulic system will be described hereafter but after a length of tubing has been bent to the form shown in Fig. 3, having bends 42 and 44 placed therein by the mechanism hereinabove described, such length of tu-bing is removed from the clamping assembly 58 and the clamping devices which secured it to the rotating segments. Such partiall formedtube is then transferred to a pair of upper clamping assemblies to have its opposite ends bent to form the U-shaped structure shown in Fig. 4.

These upper clamping assemblies and tube bending assemblies are generally similar to those heretofore described. They are provided in pairs at opposite ends of the board. Figs. 7, 8 and 9 show the mechanisms. In Fig. 7 each of a pair of hydraulically operated tube supporting assemblies is indicated by the numeral I85 and each of a pair of rotatable tube forming segment assemblies is indicated by the numeral 200. These two assemblies are connected in the hydraulic system as hereinafter described so that the two pipe supporting assemblies function simultaneously to support both ends of a length of tubing. The' two rotatable tube forming assemblies function simultaneously to bend opposite ends of the same tube.

Each tube supporting assembly comprises a tube supporting block I86 mounted upon the free end of a lever I88 which lever is swingable from its opposite end which is pivotally supported at "I8'I.' The upper working face of the block is grooved at I90 to receive and seat a tube (Figs. 8 and 18) i The lever and block are adapted to be lifted by a hydraulically operated piston and cylinder mechanism through a link I92 pivotally coupled at one end to the block I86 and at the opposite end to the piston I04. The piston is reciprocable assemblies I00 heretofore described. There is a.

arm a cylinder I96. Th opposite end of the cylinder is pivotallymounted upon a bracket I08 carried by the board 54 (Fig. 18). A coupling 202 at the outer end of the-piston I94 is adapted toslide over an inclined plane 204 secured to the board 54 to lift the block I86. As the block is lifted, the lever I88 and the piston and cylinder assembly are swung so that the block moves from the open position shown in Fig. 7 to the closed positions shown in Figs. 8 and 9.

Figs. 25 an d 18 show the free end of the cylinder-s upported for sliding movement. There is a flexible hose connection 206 which is connected with the swinging end of the cylinder I96 and forms a part of the hydraulic system. As a matter offact there Is, a flexible hose connection to the swinging end of each cylinderconnectedin the hydraulic system. U H

The two rotatable gear segment assemblies 200 are similar and are similar to the rotatable gear lower stationary rack 2I4 carried by a rack supporting bar 2I6. This bar is provided with stop screws 2I8 extending through opposite ends of the bar and adaptedto form stops to regulate the adjustment of the rack 2l4 upon the bar. The bar is secured to the board 54 by screws 220.: Screws 222 extend through the board and through slots provided in the rack 2I4 to secure the rack to the board While permitting lengthwise adjustment of the rack upon the bar. A gear wheel 224 is supported upon the rack 2I4. This gear wheelis mounted upon one end of an axle 226.

A corresponding gear wheel 228 is mounted upon the opposite end of this axle. The. board 54 is slotted as at230 to pass the axle 226 therethrough. A stationary rack 232 is supported upon the bar 234 which bar is secured to a foundation plate 236 which foundation plate is secured in spacedrelationship to the board 54 by struts 231 (Fig. 23) as hereinabove describedin connection with the base plate I30. The bar 234 is secured by screws 238 tothe plate 236 and the rack 232 is adjustably mounted upon the bar and is secured to the plate 236 by the screws 240 which screws extend through slots in the rack. Stops 24I .are provided in opposite ends of the bar 23'4 (Fig. 23) to adjustably position the rack 232 upon the bar. The gear wheels 224 and 220, travel over the stationary racks 2 I4 and 232 and are actuated by the slidable racks 242 and 244, respectively. a

'Th'e racks 242 and 244 are slidably coupled by splines 246 with rack guide bars 248 and 250, respectively, which guide bars are secured respectively to the board 54 and to the plate 236 by screws 252. The sliding racks 242 and 244 are connected by a cross-head254 which cross-head is coupled With'the outer end of a piston 256. The piston is reciprocable 'within a hydraulic cylinder 258. The cross-head 254 extends for travel through a slot 255 formed in the board 54 and similar to the slot I58 formed therein and previously described. The opposite end of the 7 cylinder 258 is pivotally supported upon a bracket ,issimilar to that of segment. I02 previously described. Mounted upon the: gear wheel 224 is clamping. mechanism similar to the clamping mechanism. hereinabove described and mounted upon the gearwheel- I04.

Theclamping mechanism comprisesa foundation plate 2l'9 secured by screws or the like to .the gear wheel-.224 (Figs .20 through 22). A link 212 is pivoted within the forked upper end of this foundation plate. The clamp proper 274 is pivoted to the outer'end of the link. The opposite end of the clamp is in the form of a hook or-jaw 216 shaped tov seat over the tube 40. to draw it into the grooved lower end 218 of the plate 2.1lland against the grooved periphery of .the'iorming segment 266. The link 2.12 is provided with the handle. 289 whereby the link may be swung to pull the hook end of the clamp up tightly against the tube as shown in Figs. 19 and 20; .In Fig. 22 the clamp isshown open. In Fig. 20.,it is shown closed against the tube 40. The pivoted end of the clampand link is swung in- .wardlytoward the board54..over the center of pivot of support for the link.

Whenthe tube supporting assemblies I85 are openedas shown in Fig- 7 a tube section 40 is placed first upon stationary supporting pins. 284 (Fig. 7 which .pins. are .fixed to the board 54. The opposite curved. ends of the tubeare positioned againstfixed abutments 286 on the board 54 (Figs. 8 and24).

When the tube supporting assemblies are hydraulically operated, the tube iselevated from .the position shown indotted outline in Fig. 7 to .tha-tshown in-Figs. 8..and 9 and the clamping mechanisms are manually actuated as described to clamp the'tube tothe tube shaping segment.

Fig.. 26 is adiagram .of the hydraulic system which is employed to actuate the mechanism ,hereinbefore. described and which carries the process to the point of forming the tube into the shape shown in Fig. 4. This hydraulic diagram Will be described hereinafter along with the description of Fig ..34. in connection with the description of theoperation.

Figs... 27. throughv 33. describezmechanism which is actuated by the hydraulic. systemshown in Fig. 34., and. which isadaptednto bend the tubular frameillustrated, in Fig.5 into the form illustrated in Fig. 6. This structureis separate from that shownin Figs. 7 through 25, but functions to carry out. and continue the sameprocess of forming a tubular seat frame andin large part embodies correspondingly similar mechanism. This structure is mountedupon a stand such as shown in Figs. 2'7 through 33.

The stand has legs 288. The end legs are connected by lower cross-pieces'290- and upper crosspi'eces 292. Upper front and rear cross-pieces 294 connect the legs at one end at the top with the legs at the opposite end. End plates 2.96 extend upwardly from-the upper endacross-pieces;- 2.92 to Support racks: and other.operatingrmechanism. A. pair of standards-298 project-up from the-.front .andarean cross-pieces v2.94adj acenteach end .of the; stand and a supporting bar 3661s mounted upon the upper ends: of .eaehpair of standards. Two of such supportingbars-300 are provided ,(Fig. 32).

A rotatable gear 310 carrying a tube forming segment 3 I 2 is supported upon a rack 302 on each end. plate 296 and is adapted to be driven by a hydraulically operated rack 316. These two gear and rack assemblies are similar. They are generally similar to the rotatable gear and tube 10 ,Iorming,segment.assembliesheretofore described. Thereisra stationary lower rack 362 supported uponabar 394 which bar is secured to the inner face of an end plate 296 by screws 306 or the like. The bar is provided at its. ends .with positioning pins 308 adapted to adjustably position the rack 362 thereon. A gear ,wheel 3!!) is supported upon the rack.3ll2. tov travel thereover. A segment 312 of a, circular disc is fixed to the gear wheel to, rotate therewith. The periphery .of this segment is grooved to seat a tube as shown in Figs. 30 and Twoof these gear wheels. 3H1 are provided. Theyare mounted upon opposite ends of an axle 314, They are disposed adjacent to the inner faces of, the end. plates 296 which carry the racks 3.02.

per racks, 3l'6'one adjacent toeach end plate and adaptedto cooperate withthe gears 310. These racks areconnected together at their rearends by a cross-bar; 318. They are driven by a pair of hydraulically operated pistonswhich form part of .a pairof piston and cylinder assemblies mounted upon the outer faces of the end plates 296.

Each uppe rack is slidably coupled with astat iona ry bar 320- secured to the inner face of the endplate 2 96 along its top margin by screws 322 or'the like (Fig; 30) 1 These twojbars 320 are connected together as a re the opposite endplates 296 by a tie rod'324- (Fig. 3i). The racks are slidable through a' guideway in the underface of each bar. A bracket-g326projects from the front end of each bar and hasa depending end portion provided with-an adjustable stop pin 328 which'forms a positioning rest for the forward slidable travel of the rack 3 I 6. v

A hydraulic piston and cylinder assembly is mounted onthe outer face of the endplate 296. There isa bracket';330- secured to the outer face of each end plate 296. 'Oneend of the cylinder 332 is journalled by a pivot pin 334 to this bracket 330' as shown in Figs. 32 and 33. This cylinder is provided with a-piston 336 whichisreciprocably racks 3| 6 are-connected by the cross-piece 3133 and the pistons are simultaneously hydraulically actuated the racks move in unison to rotate the gears 310 over the stationary racks 362.

An arm; 346 projects from each end plate 296 as shown in "Fig. 32. Each arm 340 is provided with an upstandingrear end portion 342- which carriesan adjustable stop 344 to provide a rest -forthe rearwardly outward travel of the hydraulic piston actuated racks 3 l 6.

A pair of hydraulically actuated tube forming supporting assemblies are provided one upon each end plate 296. These two assemblies are similar. Each assembly comprises a tube engaging and supporting block 348' which is mounted upon the outer end of a lever 350 which lever is pivoted at its; opposite'end at 352 to the end plate 296. The upperworking face of the block 346 is grooved as at 353' (Figs; 28 and 3 3) to seat a tube therein andhold -such tube againsta;correspondingly groovedwork-ing face: of the rotatable forming segment 3 l 2.

In"F-ig."27 the tubesupporting block 348 is 'shownas lowered and open. In Fig. 29 it -is shown as elevated raising the tube frame. A tubular frameof theshape'shown in Fig. 5 is first seated upon; supporting bars 309 as shown in 27 with the cross-piece -56 seated in notches 355 There are provided reciprocally supported upformed in the blocks 348. Such blocks have notches 351 for the other-cross-piece 52 andthe endsof the tubular frame seat in the groove 353 in the working face of the block.

This block 348 and lever 350 is elevated by hydraulic mechanism in the form of a hydraulic piston and cylinder assembly at each end of the stand. There is a hydraulic cylinder 356 journalled at 358 upon a bracket 360 which bracket iscarried by the lower cross-member 290. A piston 362 is reciprccable within the cylinder and the upper end of the piston is pivoted at 364 to the underside of the block 348 to lift the block from the position shown in Fig. 27 to that shown in Fig. 29. Such elevation of the block liftsthe tubular frame off of the supports 300 and to the position shown in Fig. 29.

Each gear wheel 3I0 is provided with clamp mechanism similar to the clamp mechanism heretofore described in connection with the construction shown in Figs. 7 through 25. There is a base portion 368 of the clamp which is fixed to the gear wheel 3I0. To one end of thisbase portion 368 there is pivoted a clamp proper 310 V by meansofa link 312'. This clamp 310 has a hook shaped outer end 316 (Fig. 32) which is shaped to engage andseat over a tube and hold such tube snugly against the grooved end of the base portion 368 and against the grooved periphery of the segment 3 I2.; When the gear wheel is rotated and rotates the segment 3I2 therewith. the tube which is held thereto is wrapped thereabout as shown in Figs. 31 and 32. I

Fig. 26 illustrates"diagrammatically the hydraulic system adapted to operate the mechanism shown in Figs. '7 through 25. There is a liquid reservoir 380 which communicates through a lead 382 with a source of liquid developing pressure 384; A pressure line 386 extends from the source of pressure 384 to each of the two valves 390 and 392. These valves are manually icontrolled being provided respectively with manually rotable valve members 39I and 393. Valve 390 controls delivery of liquid pressure to the two cylinders 94 and to the two cylinders I96. Valve 392 controls delivery of liquid pressure to the two cylinders I50 and to the two cylinders In the operation of the mechanism shown in Fig. 7 a straight length of tubing 40 is placed upon the board to be gripped by the two clamping assemblies 58 as hereinabove described. After this piece of tubing has been acted upon to shape it to the form shown in Fig. 3, it is transferred,

as'hereinabove set forth, to the position shown in dotted line in Fig; '7 or as shown in Fig. 8. Another straight length of tubing is then positioned within the clamping assembly 58.

When the manually movable valve part39I of valve 390 is moved to the position shown in solid line in Fig. 26, liquid flows from the source of liquid pressure 384 through lead 386 and the valve inlet 388 into one side of the valve and therefrom through an outlet 394 into a line 396. The lower branch of the line 396 communicates with a line 398. Line 398 leads to each of the two cylinders 94 which carry the pistons 98 and in response to the liquid pressure, the pistons are moved outwardly from the positions shown in Figs. 7 and 34 to that shown in Figs. 8 and 9 with the results heretofore described.

Line 396 has an upwardly extending branch and the liquid moves therethrough into line 400 which has two branches, one leading into one 1 cylinder I96 and the other leading into the other cylinder I96. When liquid enters the two cylinders I96 behind the pistons I94 therein, these pistons are moved outwardly from the positions shown in Figs. 7 and 26 to the positions. shown inFigs. 8 and 9. Such action clamps both tubular sections into place as shown in Figs. ,8

and 9.

When the valve 390 is disposed as shown in Fig. 26 in solid line, the valve 392 would normally have its movable valve member 393 positioned as illustrated in dotted line in Fig. 26. In such position the liquid pressure would be through the valve 392. and outlet 402 and line 404 to line 406. Line 406 has one branch leading to one cylinder I50'and another branch leading to the other cylinder I50 to hold the pistons withdrawn into the cylinders as shown in Fig. 26. A branch line 408 leads from each branch of the line 406, one branch 408 leading to one cylinder 258 and the other branch 408 leading to the other cylinder 258 holding the two pistons 256 withdrawn within the two cylinders 258 as illustrated in Fig..26. The piston and cylinder assemblies which actuate the tube forming assemblies I00 and 200 are therefore held inactive while the pistons 98 and I94 are moved'as described. V v

In the operation just described the return lead from one cylinder I96 is through line M0 to line 4I2 which line 4I2 extends between the two cylinders I94 and forms a return lead therefrom. Line 4I2 discharges through a part of line 4I4, valve inlet 4I6, one side of the valve 390, and through valve outlet 4I8 into line 420 whichline 420 leads back to the reservoir 380. The other cylinder I96 has a. return line. 422 which also communicates with the inlet 4I6 into the valve 390 to .flow therethrough and through the outlet M8 and line 420 to the reservoir. In the hydraulic system rigid or flexible leads may be provided as desired. The connections with moving cylinders is through flexible leads as heretofore stated. v

The valve 390 may be left as described with the pressure on the pistons 98 and I94 to hold the clamping mechanisms at the positions shown in Figs. 8 and 9 against the tubes. The valve 392 may now be moved from the position shown in dotted outline to that shown in solid line. In the solid line position liquid pressure will be into/the valve from lead 386 through valve inlet 424 and through the valve and outlet 426 into line 428. Line 428 communicates with a line 430 which has one branch leading to one cylinder and another branch leading to the other cylinder I50.

Line 430 has a lead 432 which extends to one cylinder 258 and has another lead 434 which extends to the other cylinder 258 of this pair of cylinders. g

When the pressure enters these cylinders I50 and 258 behind the pistons I48 and 256, these pistons are moved from positions shown in Fig. 26 to positions as hereinabove described to 1'0- tate the gears I04 and 224 and cause the tube sections to wrap around the gear segments I02 and 266 as hereinabove described.

The liquid return from the cylinder I50 upon movement of the pistons outwardly is through outlets 436 which communicate with line 406 and through 404, valve inlet 402, valve 392 and return line 420 lead back to the reservoir 380. The liquid return from-the cylinders 258, upon move ment of the pistons outwardly, is through out- 13 lets 408, lines 406, 404, 402 and valve 392-and line 420 to the reservoir.

The hydraulic diagram shown in Fig. 34 is that provided to operate themechanism shown in Figs. 27 through 33. In this mechanism there are'two pairs of hydraulic piston and cylinder'assemblies. One'pair of hydraulic piston and cylinder assemblies includes cylinders 356 which carry pistons 362 which swing the tube holding and bending blocks-348 to hold the tube frame up against the forming segments 3!2. The other pair of cylinder and piston assemblies includes cylinders 332 provided with pistons 336 which actuates the racks 3!6' to roll :the gears 3!!! to wrap the tubes about the segments 3l2.

The. hydraulic system shown in Fig. 34includes a; reservoir440 for liquid which communicates through a lead"442'with a liquid pressure source 444. The source of liquid pressure 444 has a line 446 which extends to two valves 448 and 450, respectively. When the pistons 362 are disposed as shown in Fig. 27, the tube holding blocks 24B are down so as to permit insertion of the tubular frame as shown in Fig. 27. When it is desired to lift this frame from the position shown in Fig. 27 to that shown in Fig. 29, the valve member 449 of valve 448 is moved to the position shown in solid line in Fig. 34. In such position liquid pressure moves from the source 444 through lead 446, valve inlet 452, into and through the valve 446 and out of the valve through a lead 454 to a line 456. This line 456 has two branches which lead to the two cylinders 356. When the pressure is built up in these cylinders, the pistons 362 are advanced from the positions shown in Fig. 27 to that shown in Fig. 29.

The return of liquid from these cylinders 356 is through a return line 458 which leads from each cylinder 356 and through a line 466 back through the valve 448 and out of the valve through an outlet 462 and a line 464 communicating with such outlet and leading to the reservoir 44!].

When the valve 448 has its valve member 445 positioned as shown in solid line in Fig. 34, the rotatable valve member 45! of valve 456 is normally initially disposed as shown in dotted line. After the pistons 362 have been advanced and the tubular frame elevated to the position shown in Fig. 29 and clamped to the forming segments of the gear wheels as heretofore described, the valve member 45! is moved from the dotted line position of Fig. 34 to the solid line position there shown. The valve 448 will be left in the position shown in solid line during this operation of valve member 45!.

When the valve member 45! is positioned as shown in solid line in Fig. 34, liquid pressure enters one side of the valve 456 through a lead 466 from line 446 and flows through the valve and out through an outlet 468. The outlet 468 leads to a line 4'16 which has two branches. One branch leads to one cylinder 332 and the other branch leads to the other cylinder 332 of this pair of cylinders. When liquid pressure enters these cylinders 332 behind the pistons 336 therein, such pistons being withdrawn into the cylinders as shown in Fig. 34, the pistons are moved outwardly from the positions shown in Figs. 34 and 27 to that shown in Fig. 32. The return for liquid from these cylinders 332 is through leads 412 into line 414 which communicates through a line 416 with one side of the valve 450 and flows therethrough and through the line 464 back to the reservoir 44!]. As stated heretofore the leads of the hydraulic system are rigid or flexible as asetm'z 14 thesitu'aition demands. "'I'heshowing-in Figs;-26 and 34=is diagrammatic only.

What -I claim is:

'1.=Tube bending mechanism comprising, in combination, a generally upright foundation board, clamping means adapted to secure a tube to one 'faceof the board, a pair of tube engaging blocks swingably-mounted upon the board, each -block-having a tube engaging linear face, means operable" to move said blocks to engage the tube at spaced points, andtobend opposite ends of the tube and to support said bent ends along linear paths, a pair of racks mountedupon-the-board one parallel to each of said linear paths, a gear supported to,-.revolve,-over, each-rack, a tube forming part having an arcuate tube forming face securedto each gear to rotate therewith, means for clamping opposite end-portions of atube to Said tube forming parts to wrap thereabout as the parts revolve with the gears; and means for revolving said gears along said racks toward each other.

2. Tube bending mechanism comprising, in combination, means for holding a portion of a straight length of tubing with one end projecting beyond the holding means, a tube forming roll supported for rotation and translation along a determined path generally lengthwise of the end of the tube projecting beyond the support but angularly with respect thereto, said roll having a grooved arcuate tube forming face, a tube supporting block having a grooved arcuate tube supporting face adapted to provide a seat for a length of tubing, said block swingably supported beyond the tube holding means to be swung to engage the projecting end of tubing to bend the same to and to support the same at a position parallel to the path of translation of the roll, means for clamping said projecting end of tubing to the tube forming face of the roll, and means for advancing the roll revolvably lengthwise of the block supported projecting end of tubing to wrap the tubing about the roll.

3. Tube [bending mechanism comprising, in combination, tube supporting means adapted to hold the intermediate portion of a length of tubing in a straight line supported position with the ends thereof projecting beyond the supporting means, a tube forming roll supported for rotation and translation along a path extending generally lengthwise of but angularly with respect to a projecting end of the tubing beyond said supporting means, said roll provided with a grooved arcuate tube forming face, a block pivotally supported beyond one end of the supporting means adapted to be swung from a position on one side of the projecting end of tubing to bend the same to a position parallel to the path of translation of the roll and to support the same at said last named position, means for clamping the projecting end of the tubing to the tube forming face of the roll, and means for advancing the roll along its path of translation to wrap that portion of the tubing clamped thereto about the roll.

4. Tube bending mechanism comprising, in combination, clamping means adapted to hold a portion of a length of tubing in a straight line position with one end of the tubing projecting beyond said means, a tube forming roll having a grooved arcuate tube engaging face, said roll supported for rotation and translation along a path extending angularly with respect to the straight line supported portion of the tube, a tube engaging block swingably supported 15 beyond one end of said clamping means to [be swung to engage and bend that end of the tube projecting beyond said means to a position parallel to the path of translation of the roll, means for clamping the projecting end of the tube ad- .iaeent to one end of the block to the tube forming face of the roll, and means for advancing the roll along its path of translation to wrap the block supported portion of the tube thereabout.

' AXEL V. BROGREN.

REFERENCES CITED The following references are of record in the file of this patent:

Number Number Name Date Brown Aug. 28, 1906 Kitouski Jan. 1, 1918 Nelson Dec. 24, 1918 Brinkman 1 July 8, 1919 Claybourn Oct. 14, 1919 Francis Mar. 15, 1932 Meyer Mar. 14, 1933 Mitchell May 19, 1936 Fiegel Nov. 2, 1937 Brooks June 16, 1942 Duer Feb. 8, 1944 Woodburn June 18, 1946 FOREIGN PATENTS Country Date France Jan. 21, 1929 France Oct. 21, 1930 France Apr. 4, 1931 

